Thumb turn device for closure locks



Nov. 4, 1952 D. N. JEWETT THUMB TURN DEVICE FOR CLOSURE LOCKS Filed Sept. 27. 1949 Patented Nov. 4, 1952 UNITED STATES PATENT OFFICE I r I I I 2,616,738

THUMB TURN DEVICE FOR CLOSURE LocKs Deane N. J ewett, Detroit, Mich., assignor to De- 'troit Hardware Manufacturing Company,-Detroit, Mich., a corporation of Michigan Application September 27, 1949, Serial No. 117,962

This invention relates to closure 'locks, such casing which is alternatively arranged to receive a key-actuated cylinder lock, such as on the inside of the door." Prior thumb turn attachments have been designed to slide into the opening andbe secured by tabs, with lugs to prevent turning of the attachment in the opening, and with a screw to anchor the attachment in position. f Such prior thumb turn attachments, however, have been inaccurate and have fitted loosely into the opening, due to the necessity of providing enough clearance for the lugs. or removal of these prior attachments has been found difiicult, due to the difficulty of getting the lugs into or out past the threads of the opening.

One object of the present invention is to provide a thumb turn device for closure locks which is providedwith threads so as to be threaded into the threaded opening which alternatively receives a cylinder lock, means being provided to prevent the device from rotating when it has been once secured in its intended position.

Another object is to provide a thumb turn device for closure locks of the foregoing character wherein the lugs hitherto provided are completely' eliminated, thereby enabling the device to be firmly and accurately secured in the opening without the looseness or wobbling characteristics of prior thumb turn devices.

Another object is to provide a thumb turn device for closure locks of the foregoing character wherein a simple yet positive spring-actuated mechanism is provided for urging the operating shaft of the device into a predetermined position so that the user by the sense of touch alone can readily determine when the operating cam of the device is in its withdrawn position, thereby insuring that the bolt of the lock isseated in its keeper.

In the drawings:

Figure l is a side elevation, partly in section along the line I--I in Figure 2, of a closure lock equipped with a thumb turn device according to one form of the present invention;

Figur'e2 is a cross section taken along the line 22 in Figure 1;

1 Claim. (01. 292-440) Figure isa front elevation of the thumb turn device similar to that. shown in Figure l, but with the device removed from the lock and with the operating cam cutaway;

Figure 4 is a front elevation of a spring mounting plate and cam retainer used in the thumb turn device of Figures 1 to 3 inclusive;

Figure 5 is a side elevation of the mounting plate shown in Figure 4;

Figure 6 is a sideelevation of the operating cam used in the thumb turn device of Figures 1 to 3 inclusive; and

Figure 7 is a cross-section taken along the line 1-1 in Figure 6.

Referring to the drawings in detail, Figures 1 and2 show 'a closure lock, such as a door lock,

Moreover, theinsertion generally designated I2, equipped with one of the thumb turn devices of the present invention, generally designated. The door look In is of any conventional and convenient type and its details are beyond the scope of the present invention. Such a door lock is disclosed and claimed in the co-pending Jewett application, Serial No. 114,422 filed September 7, 1949, for Closure Lock, hence a brief description thereof will suffice. The door look It] is designed to fit into an elongated aperture I2, such as a rectangular aperture, in the edge wall I3 of a door, generally designated I4." The door I4, only a fragment of which is shown in Figures 1 and 2, may be of a hollow metallic construction with opposite side walls I 5 and I 6 respectively (Figure 2). The side wall I5 is'provided with a circular hole IT for receiving a'conventional cylinder lock, generally designated. I8, whereas the opposite side wall I5 is provided with .a smaller opening I9 for the passage of a squared shaft 20 journaled in a mounting plate or disc 2I and retained in position by an annular enlargement 29a. Mounted on the shaftZIlis a handle orknob 22 provided with a square shaft socket 23 in which the shaft 20 is secured as by the pin 23a. The mounting plate 2| is secured by screws'26 in threaded holes 25 in the door side wall I5 (Figure 2). The inner end of the square shaft 20 is secured to the thumb turn device in a manner described below.

The cylinder lock I8, which occupies the opposite hole H in the door side wall I6 (Figure 2) ,is of a conventional pattern well-known to lock- .backed up by a beveled escutcheon plate or disc 28. The face 21 is provided with a key receiving 3 portion 29 containing the usual keyhole or key recess (not shown). This recess opens into the interior of the cylindrical body 26, which is hollow and which contains mechanism, such as tumblers, for selectively locking and unlocking a rotary shaft 33 (Figure 2) carrying a bolt operating cam 3| secured thereto by the fastener 32. The cam 3| is of approximately the same shape as the cam subsequently to be described in connection with the thumb turn device The exterior of the cylindrical body 26 is provided with threads 33 by which it may be threaded into the correspondingly threaded opening 34 in the side wall 35 of the door lock case 36, axial grooves or notches 31 being provided for the reception of anchoring set screws 28 similar to the anchoring set screws subsequently to be (1G1 scribed in connection with the thumb turn' device E l.

The lock case 35 is a hollow box-like structure having oppositely projecting tabs 39 (Figure l) by which it is secured, as at 40, to the lock front plate The plate M is of a length and width adapted to fit snugly into the aperture |2 in the door edge wall l3, and carries rotatable eccentric discs 42 pivotally mounted thereon as at 43 to swing upward or downward and provided with screw holes 55 for receiving anchoring screws 45 threaded through screw holes 45 in the door edge wall E3. The front plate 4| is provided with a pair of access holes 47 (one only being shown in Figure 1) through which headless pointed set screws 68 are inserted and threaded through aligned threaded holes 43 in the lock case 36 to engage one of the notches 3'! in the cylinder lock body 26 and also to engage a corresponding notch in the thumb turn attachment II, as described below.

The lock case 35 is provided with a bore 50 of rectangular cross-section adapted to slidably receive a lock bolt 5! of similar rectangular crosssection. lhe bore 55 is aligned with a corresponding hole 52 (Figure 1) through which the bolt 5| reciprocates to enter and leave its keeper (not shown). The bolt 5| is provided with a U-shaped cutaway portion 53 from which a slot 54 extends downward. The slot 54 contains a vertically slidable tumbler pin or detent member 55 having wings 55 extending laterally in opposite directions into slots 5'! in the opposite side walls 35 of the lock case 35. The slots 51 are provided with spaced pockets or notches 58 and 59 separated by downwardly projecting barriers 60 over which the wings 56 must pass in order to move from one pocket 59 to the other pocket 58 as the bolt 5! is being advanced or retracted. This mechanism prevents the bolt 5| from being reciprocated by a screw driver or other instrument inserted in the crack of the door, and the member 55 is constantly urged upward by a compression spring 55 having its lower portion engaging the bottom of the slot 54 and its upper end engaging the bottom of an inverted socket 62a on the lower side of the member 55.

The tumbler pin or detent member 55 is actuated either by the key-operated cam 3| of the cylinder lock i8 or by the knob-operated cam 62 of the thumb turn device Thecam 62 consists of an arm 53 of roughly keyhole shape outline Figures 1 and '7) carrying a central hub 64 in the form or" a boss of generally circular crosssection with flattened parallel side portions 55 and with a bore 65 of square cross-section adapted to receive the inner end portion ot the squared shaft 23. The hub 65 is provided with an annular groove 51 (Figure 6), adapted to receive the edges of the U-shaped notch 68 formed in the lower edge of the spring mounting plate 69 of the thumb turn device ll. The latter is provided with an anchoring tab ill which is struck up therefrom for the purpose of anchoring the bridge portion 7| of a spectacle-shaped or U-shaped spring 12 (Figure 3) having opposite parallel arms '13 adapted to engage the flattened side portions 55. Spring loops 14 are interposed between the arms 73 and bridge portion 1| of the U-shaped spring 2 to increase the resilience thereof.

The spring mounting plate 59 is of circular outline and is seated in a recess 75 likewise of circular cross-section in a case 15 of cylindrical form. The mounting plate 69 is secured within the recess F5 by being staked therein, as at H (Figure 3). The staked portions i1 are formed by indenting the edge wall 73 of the recess I5 by a suitable tool, thereby accurately positioning the assembly of the mounting plate 59 and U-shaped spring E2 in position within the recess 15.

The outer surface of the case 25 is threaded as at T9 to enter the correspondingly threaded opening 34 in the side wall 35 of the case 36 (Figure 2), similar to the opening 34 occupied by the threaded body 25 of the cylinder lock IS. The case 16 is provided with a hole or bore in which the hub 65 of the cam 63 is journaled. Diametral slots or recesses 8| are provided in the case 15 for receiving a spanner by which the thumb turn device II is threaded into the opening 35. The periphery of the body 76 is provided at intervals with notches 82 (Figure 1) for receiving the pointed ends of the set screws 48, to prevent rotation of the thumb turn device after it has been once properly located in the opening 34.

In the operation of the invention, let it be assumed that the thumb turn device I I has been threaded into the opening 34 and connected to the squared shaft 20 in the manner shown in Figure 2 As a consequence, when the operator grasps the knob or handle 22 in his fingers and rotates it, the consequent rotation of the squared shaftZEl swings the cam 62 downward into the notch 54 and into engagement with the upper end of the tumbler pin or detent member 55, as shown by the dotted lines in Figure 1. The continued rotation or swinging of the cam 62 in a clockwise direction forces the tumbler pin 55 downward, so that the wings 53 move out of the pockets or notches 53. At the same time, the subsequent engagement of the cam 62 with the forward side wall of the notch 54 reciprocates the bolt 5| to the left, moving it outward through the hole 52 in the front plate 4| as the wings 56 move over the barriers 55 into the notches 58 (Figure 1.).

With the wings 55 now seated in the notches 58, the bolt 5| is prevented from being pried open by the use of a screw driver in the door crack. Consequently, only the insertion of a key in the cylinder lock portion 29 so as to operate the cam 3|, or the opposite rotation of the handle 22 to swing the cam 52 in a counterclockwise direction will retract the bolt 5| and unlock the door. As the cam 62 is swung upward into the position shown in Figures 1 and 2, the spring arms 73 come to rest against the flat portions 65 of the cam hub 54, notifying the operator through his sense of touch that the cam 62 is in a vertical position with the bolt 5| either fully extended or fully retracted, as the case may be. a

In the drawings, the cams 3| and 62 have been shown as of a single end type. It will be obvious, however, that the arms 63 of the cam 62 may extend in opposite directions from the hub 64 so as to form a double-ended cam, if desired.

What I claim is:

A thumb turn device adapted to fit into the circular threaded cylinder lock opening inthe housing of a closure lock for actuating the lock bolt without a key, said device comprising a disc having a circular periphery with external threads thereon corresponding to the threads of said opening and adapted to be threaded therein, 15

said disc having a shaft bearing therein, a rotatable shaft rotatably mounted in said bearing, a thumb knob secured to the outer portion of said shaft, and a bolt-operating cam includin an arm mounted on the inner portion of said 6 shaft remote from said thumb knob and operatively engageable with said lock bolt in response to the rotation of said rotatable shaft.

DEANE N. JEWETT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 8,158 Yale et a1 Apr. 2, 1878 152,774 Steele July 7, 1874 1,089,435 Page Mar. 10, 1914 2,327,071 Schlage Aug. 17, 1943 FOREIGN PATENTS Number Country Date 517,056 Great Britain Jan 18, 1940 

